i think it was violation of CRC rules:
Running in to the car ahead of you
RA-1: The onus is on the behind driver to take all necessary care and responsibility not to run into an ahead driver.
RA-2: The ahead driver must not do any malicious or inappropriate braking or slowing. The ahead driver is entitled to be slower or use longer and earlier braking zones than others. They are also entitled to turn in earlier or later and/or apex earlier or later. They are also entitled to be inconsistent and erratic.
Running in to the car ahead of you
RA-1: The onus is on the behind driver to take all necessary care and responsibility not to run into an ahead driver.
RA-2: The ahead driver must not do any malicious or inappropriate braking or slowing. The ahead driver is entitled to be slower or use longer and earlier braking zones than others. They are also entitled to turn in earlier or later and/or apex earlier or later. They are also entitled to be inconsistent and erratic.